Maximum XNET Sessions

[dhaugen92]

I am getting Error -1074384879 at XNET Create Session:2080003. Possible Reason(s): NI-XNET: (Hex 0xBFF63011) The maximum number of sessions was exceeded. Solution: Use fewer sessions.

What is the maximum number of sessions? Is closing a session with the XNET Clear.vi enough, or is there further steps to purge the session from memory that must be taken? This is for an application that is running 24/7 that creates and destroys sessions for every 'sequence' start, which is about once every three minutes. I am properly creating the sessions, and closing them at the end of every 'sequence' with the XNET Clear.vi, but am still getting this error.

[dhaugen92]

Sequence runs "Start CAN" and "Stop CAN" steps, program never shuts off, and hundreds of sequences run per day. This attached picture is what I have for the "Stop CAN" step, but I am still getting the error..

[the_mitten]

Hi Dan,

What version of XNET are you using? In version 14.1 and below, there was a limitation of 512 total frames per interface. You can create more than 512 sessions, but the frame limit must be maintained.

Regards,

[dhaugen92]

I am using the latest version of XNET (16.1 I believe). The error I am getting does not say anything about # of frames. It only says 'maximum number of sessions reached'.

[the_mitten]

Hmm. How often is the error occurring - is it consistent or intermittent? 

According to this article the maximum number of Frame Input Streams per interface is limited to 8 per interface, while overall the maximum number available for the system is 8192.

If it is occurring only intermittently, could there be circumstances in the code in which an attempt is made to create a new session, prior to clearing the existing sessions?

Regards,

[dhaugen92]

It pretty much always happens, just takes a little while. something like 30-40 sequences or so can run before this error happens. But all the sessions are in an array and sent into a for loop with the 'close session' xnet VI

[OEM_Dev]

I had a program that functioned exactly as you described and got the same error. I was never able to resolve it (or track down why it happened consistently but with no clear pattern why), I ended up changing the xnet code to only open 1 session that I left open between sequences 

[dhaugen92]

Interesting... 

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@OEM_Dev wrote:

I had a program that functioned exactly as you described and got the same error. I was never able to resolve it (or track down why it happened consistently but with no clear pattern why), I ended up changing the xnet code to only open 1 session that I left open between sequences 

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And it was never root caused?

[mpanganiban]

Hi,

I did not create a new discussion thread because my concern is related to this topic.

I created a VI that checks the maximum number 'Stream' sessions we can create in one CAN physical port. It seems that we can create 8 maximum 'Stream' sessions wherein Frame In Stream and Out Stream are sharing for this limit.
What surprises me is that creating 'Frame In Queued' session set to J1939 application protocol is also consuming the limit of session you can create. Is this true?

Please see attached VI for you to test it.

Resources Used:

LabVIEW Version: LV2015 SP1

XNET Version: XNET 16.1

HW: NI USB-8502

Questions:
1. From this link, http://digital.ni.com/public.nsf/allkb/B6B0BF61BB8C90028625810200595A1F?OpenDocument, explanation is not clear regarding maximum limits because J1939 Frame In Queued session seems to be sharing also with the maximum limit of 8 session. And what surprises me is that one XNET J1939 Frame In Queued Session is allocating two sessions.
Is there any XNET documentation(with more details about maximum session) I can refer to?

2. Why the error is referring to number of frames? I am expecting Error -1074384879 here which is: NI-XNET:  (Hex 0xBFF63011) The maximum number of sessions was exceeded. Solution: use fewer sessions.

Thanks.

With Best Regards,

Michael

[even-And]

For future reference, creating a new post and linking to an old one is a better option. There is a higher potential for more people to see the new post rather than commenting in an old post.